Rigid polyvinyl chloride resins having enhanced resistance to deterioration due to the presence of an organotin unsaturated half ester and an unhindered phenol



United States Patent Office Patented Dec. 9, 1969 3,483,159 RIGID POLYVINYL CHLORIDE RESINS HAVING ENHANCED RESISTANCE T DETERIORATION DUE TO THE PRESENCE OF AN ORGANOTIN UNSATURATED HALF ESTER AND AN UNHIND- ERED PHENOL Otto S. Kauder, Jamaica, N.Y., assignor to Argus Chemicsal Corporation, Brooklyn, N.Y., a corporation of New ork No Drawing. Continuation of application Ser. No. 474,980, July 26, 1965. This application May 22, 1967, Ser. No. 640,425

Int. Cl. C08f 45/58, 45/62 U.S. Cl. 260-4555 8 Claims ABSTRACT OF THE DISCLOSURE The resistance to deterioration when heated of rigid polyvinyl chloride resin compositions is improved by incorporating therein a stabilizer composition containing an organotin compound having organic radicals linked to tin only through carbon and oxygen wherein at least two of the radicals are linked through carbon and at least one radical is linked to tin through oxygen to a carboxyl group of a half ester of an unsaturated aliphatic dicarboxylic acid with an alcohol having from one to two hydroxyl groups, and a phenol compound having at least one hydrogen atom ortho to a phenoilic hydroxyl group.

This application is a continuation of application Ser. No. 474,980, filed July 26, 1965, now abandoned, which was a continuation-impart of application Ser. No. 164,974, filed J an. 8, 1962, and now abandoned.

This invention relates to rigid, i.e. unplasticized, polyvinyl chloride resin compositions containing an organotin compound and a phenol compound containing at least one hydrogen atom ortho to one hydroxyl group and having, as a result, an improved resistance to deterioration when heated at temperatures of 375 F. and higher.

Many organotin compounds are now widely recognized as the best available single-compound stabilizers for polyvinyl chloride resins. Even the best of these, however, is not always satisfactory.

Numerous types of organotin compounds have been proposed for stabilization of polyvinyl chloride resins, among them, the alkyl tin mercaptides and alkyl tin mercaptoesters described in U.S. Patent Nos. 2,914,506 to Mack, 2,801,258 and 2,891,922 to Johnson, 2,726,254 and 2,870,119 to Leistner, 2,726,227 to Leistner, and 2,641,588

to Leistner, and 2,954,363 to Kuehne; the alkyl tin mercaptoacid ester compounds, described in U.S. Patent No. 2,641,596; the alkyl tin amides of thio acids described in U.S. Patent No. 2,704,756 to Leistner; and the alkyl tin cyclic glycol thio acid esters described in U.S. Patent No. 2,752,325 to Leistner; the alkyl tin xanthates described in U.S. Patent No. 2,759,906 to Leistner; and the alkyl tin esters of mercapto alcohols of U.S. Patent Nos. 2,870,119, 2,870,182, 2,872,468 and 2,883,363 to Leistner et al.

These organotin compounds have in common a hydrocarbon group directly attached to tin through a carbon atom, and a sulfur-containing radical attached to the tin through the sulfur atom. This combination of radicals is recognized as giving optimum stabilization, from the standpoint of clarity and minimizing loss of hydrogen halide from the resin. However, sulfur-containing radicals introduce an odor problem.

Several types of organotin compounds have been suggested in which the tin is not linked to sulfur. These compounds have a hydrocarbon group directly attached to tin through a carbon atom, and an oxygen-containing group, such as an alkoxy or an ester group, attached to tin through oxygen. Typical of these compounds are those described in U.S. Patent Nos. 2,938,013, to Mack et al. and 2,680,107 to Leistner et al. However, the oxygen-containing radicals do not impart as good a stabilizing efiect as sulfur radicals.

U.S. Patent No. 2,307,157 to Quattlebaum et al. suggests the use of sulfur-free organotin carboxylates as the sole color-stabilizing agents for vinyl chloride compositions. These compounds are not as effective as sulfurcontaining compounds, although certain compounds, such as, for example, the bis-(dialkyltin monoester) maleates, complex compounds containing two tin atoms per molecule, give some degree of protection.

Leistner et al. in U.S. Patent 2,564,646 disclose the use of organic phosphites as anti-clouding agents in conjunction with polyvinyl chloride stabilizers including various organic and inorganic lead salts, calcium, strontium, barium, cadmium, zinc, and tin salts of fatty acids, various organotin compounds including dibutyl tin oxide, dibutyl tinlaurate, dibutyl tin maleate, and tetraphenyl or tetraalkyl tin. The patentees state that if less effective anticlouding action is acceptable, then the phosphites can be replaced by organic sulfides or by hindered phenols. As indicated in the Leistner et al. patent, a hindered phenol is a phenol in which there are alkyl groups ortho to each phenolic hydroxyl group and hence in which there are no hydrogen atoms in the ortho position.

In accordance with the present invention, rigid polyvinyl chloride resins having improved resistance to deterioration when heated at 375 F. for up to one hour are provided comprising an organotin compound free from sulfur, but having as good a stability as polyvinyl chloride resins containing an organotin sulfur compound, and less odor. The rigid polyvinyl chloride resins of the invention comprise a phenol compound and an organotin salt of a half ester of an unsaaturated aliphatic dicarboxylic acid. The phenol compound should contain at least one hydrogen atom ortho to a hydroxyl group and alone imparts no observable stabilizing effect, but synergizes the stabilizing eflfect of the organotin compound such that both together are far more effective than either alone.

The rigid polyvinyl chloride resin is afiorded optimum protection by means of the stabilizer combination of this invention.

The organotin compounds may be characterized as having organic groups linked to tin by means of carbon and/ or oxygen atoms only.

The organotin compound can be either monomeric or polymeric but is preferably monomeric. The preferred organotin compounds used in the invention can be further defined by the formula:

( I) ug l 2) up In the above formula, R and R are hydrocarbon radicals having from about one to about thirty carbon atoms, which can contain inert substituent groups such as halogen, ether and ester groups.

R can, for example, be an aliphatic group such as alkyl and alkenyl, cycloaliphatic group such as cycloalkyl and cycloalkenyl, or heterocyclic group, such as methyl, ethyl, propyl, propenyl, isopropyl, n-butyl, butenyl, vinyl, isobutyl, tert-butyl, sec-butyl, amyl, hexyl, oetyl, oleyl, 2- ethylhexyl, iso-octyl, lauryl, stearyl, behenyl, allyl, furfuryl, cyclohexyl, cyclopentyl, tetrahydropyranyl and tetrahydrofurfuryl.

3 The group can be derived from an organic mono or poly carboxylic acid, saturated or unsaturated, of the formula R COOH including aliphatic, aromatic, cycloaliphatic and heterocyclic acids, which can c ntain inert substituents such as halogen, hydroxyl, keto and alkoxy groups, such as, for example, acetic acid, propionic acid, oleic acid, ricinoleic acid, linoleic acid, stearic acid, butyric acid, valeric acid, chloroacetic acid, hexanoic acid, octanoic acid, lactic acid, levulinic acid, 4-meth xy butyric acid, lauric acid, behenic acid, linoleic acid, palmitic acid, benzoic acid, methylbenzoic acid, cyclohexane carboxylic acid and furoic acid.

R is a hydrocarbon group having from about one to about thirty carbon atoms and containing an ethylenic double bond. The ethylenic double bond is located such that in an acid of the formula the said double bond is alpha to a carboxyl group. The R groups are derived from alpha unsaturated dicar- 'boxylic acids containing from about four to about ten carbon atoms, such as maleic acid, fumaric acid, itaconic acid, glutaconic acid, 2-hydromuconic acid, citraconic acid, 2-hexene-1,4-dicarboxylic acid, 2-octene-1,8-dioic acid, cyclohexene-1,2-dicarboxylic acid and 2,5-heptadienedioic acid.

R is an organic group derived from a monohydric or polyhydric alcohol of the formula R OH) M where n, is an integer from one to about four but is preferably one or two. Thus, R, can be alkyl, alkylene, alkenyl, aryl, arylene, mixed alkyl-aryl, mixed aryl-alkyl, cycloaliphatic and heterocyclic and can c ntain from about one to about thirty carbon atoms and can also contain ester groups, alkoxy groups, hydroxyl groups, halogen atoms and other inert substituents. Preferably R is derived from dihydric alcohols, such as glycols containing from two to about thirty carbon atoms, including ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, tetramethylene glycol, neopentyl glycol and decamethylene glycol or from monohydric alcohols containing from one to about thirty carbon atoms, such as methyl, ethyl, propyl, n-butyl, t-butyl, isobutyl, octyl, decyl and lauryl alcohols.

The sum of n 11 and n is four, n is either two or three, n can range from one to two and 11 can range from zero to one. Preferably, n is either one or two and n is either zero or one.

The following organotin compounds are typical of those coming within the invention:

The preferred phenol compounds are phenol having the structure wherein R can be hydrogen, alkyl, aryl, alkenyl, alkaryl, aralkyl, cycloalkyl hydrocarbon groups containing from CH3 5 -]1oC-CH=GH-CO( JHCH2O-CHg-$H-OH i I1 I CH3 s CH;

one to carbon atoms, heterocyclic, alkoxy, halogen 30 or acyl OCOH=OHO-OOHs u u [R ffs O 0 0 CH SnOCCH=CH-GO on 17. 0 I H ll l where R is aryl, alkyl or hydrogen], and sis an integer 6 s i from one to four. Representative monocyclic phenols include guaiacol,

resorcinol Inonoacetate, vanillin, butyl salicylate, 2- tertiary butyl-4-methoxy phenol, nonyl phenol, dodecyl phenol, 2,4-dinonyl phenol, phenyl phenol, 2,3,4,5-tetra 00 C CHzCHCO 0 02115 decyl phenol, tetrahydroalpha-naphthol, eugenol, isoeugenol, thymol, glyerine monosahcylate, methyl-p-hyi OfiTOZHEE droxybenzoate, ethyl-p-hydroxy-cinnamate, 4-benzyloxy- 04119 0 phenol, p-acetylaminophenol, p-stearoyl-aminophenol, p-

dichlorobenzoylaminophenol and p-hydroxysalicylanilide.

In the case of bicyclic phenols, the rings can be linked by oxyether groups or by alkylene, alicyclidene or arylidene groups. Such bicyclic phenols can be defined by the formula:

These compounds are readily prepared by conventional methods as by reacting the corresponding organotin oxides With the appropriate organic carboxylic acids. A

typical reaction for such a preparation is as follows: 0H,] 0H" Additional details on the preparation of organ'otin compounds can be had by reference to the publication, The wherein Z i a Single b or an oxygen atom an Development of the Organotin Stabilizers by H. Verity alkylene or alicyclidene or arylene or a mixed alkylene- Smith (The Tin Research Institute, Middlesex, England, alicyclidene or alkylene-arylidene group, having a straight or branched chain, Whose total number of carbon atoms preferably ranges from one to about ten, y and y are of this invention is a phenol compound containing at g: gl gg gi g fi iggpt ig %f g gz zg 223$? least one hydrogen atom ortho to at least one phenolic gen alkyl of one to about ten carbon atoms Pref hydroxyl group. The phenol compound, 1n addition, preferably the OH groups are ortho and/O1. para to Z, and

The second component of the stabilizing combination erably does not Contain two free hydroxyl groups P there must be a hydrogen atom ortho to at least one OH to each other on any phenyl ring as in hydroquinone. i h l l The aromatic portion of the molecule can be substituted The sum of y and n in each ring cannot, of course,

or unsubstituted. exceed five.

Typical Z groups are The various Z and Q groups are exemplified in the following compounds.

Exemplary polyhydric phenols are 2,2-bis(4-hydroxy phenyl) propane,

methylene-bis-(p-cresol),

4,4-oxobis-(3-methyl-6-isopropyl phenol),

2,2'-oxobis- (4-dodecyl phenol),

4,4'-n-butylidenebis-(Z-tertiary butyI-S-methylphenol),

4,4benzylidenebis-(Z-tertiary butyl-S-methylphenol) 4,4'-cyclohexylidenebis-(Z-tertiary butylphenol) 1,1,3 tris (2 methyl 4' hydroxy 5' tertiary butylphenyl) butane.

These stabilizing combinations, as has been indicated are particularly effective stabilizers for polyvinyl chloride resins of all types, by whatever process they are prepared, including solution-polymerized, emulsion-polymerized and suspension-polymerized resins, to name only a few. The term polyvinyl chloride as used herein is inclusive not only of polyvinyl chloride homopolymers of all types, and after-chlorinated polyvinyl chloride, but also of copolymers of vinyl chloride in a major proportion, and other copolymerizable monomers in minor proportion, such as copolymers of vinyl chloride and vinyl acetate, copolymers of vinyl chloride and vinylidene chloride, copolymers of vinyl chloride and acrylonitrile, copolymers of vinyl chloride with maleic or fumaric acid esters and copolymers of vinyl chloride with styrene, and also mixtures of polyvinyl chloride resins in a major proportion with a minor proportion of other synthetic resins, such as chlorinated polyethylene, or copolymers of acrylonitrile, butadiene and styrene. Among the polyvinyl chlorides which can be stabilized are the uniaxially-stretch-oriented polyvinyl chloride described in US. Patent No. 2,984,593

to Isaksem et al., that is, syndiotactic polyvinyl chloride, I

as well as atactic and isotactic polyvinyl chlorides.

The amount of phenol and organotin compound employed is sufficient to impart the stabilizing effect desired. A polyvinyl chloride resin composition which is to be subjected to high temperatures will ordinarily require a larger amount of the stabilizing combination of the invention. An amount of phenol as little as 0.01 part by weight per 100 parts of polyvinyl chloride resin will enhance the stabilizing effect of the organotin compound, and such as amount together with an amount of organotin compound as little as 0.25 part by weight per 100 parts of polyvinyl chloride resin will, in general, give a polyvinyl chloride resin composition stable at temperatures up to 375 F. or higher. There is no critical upper limit on the amount of either phenol or organotin compound. At amounts beyond about 2 parts of phenol and about 10 parts of organotin compound, the increase in stabilizing effect may not be commensurate with the amount that is employed, and such amounts accordingly, may be wasteful, and uneconomic. However, larger amounts than these can be employed, and may be necessary under some conditions. Preferably, for optimum results, the amount of phenol is within the range from about 0.01 to about 2 parts, and the amount of organotin compound is within the range from about 0.5 to about 5 parts, by weight per parts of resin.

The stabilizing combination of this invention can, if desired, be employed in conjunction with other stabilizers for polyvinyl chloride resins, such as, for example, organic compounds containing at least one epoxy group. Typical organic epoxy compounds are described in US. Patent No. 2,997,454, the disclosure of which is hereby incorporated by reference. Such additional stabilizers can be used where special stabilization effects are desired. Ultraviolet absorbers can be utilized in conjunction with the stabilizing combination of the invention.

Should the stabilizer combination of the invention be employed together with other polyvinyl chloride resin stabilizers, the amount 'of the stabilizer combination of the invention together with the other stabilizer will be sufficient to impart the desired stabilizing effect. The stabilizer combination of the invention in such event will be the major stabilizer, and the additional stabilizer will supplement the stabilizing action of the former, the amount of the stabilizer combination being within the range from about 0.26 to about 12 parts by weight per 100 parts of the resin, and the additional stabilizer being in an amount of from about 0.05 to about 10 parts per 100 parts of the resin.

These stabilizing combinations, as has been indicated, are particularly effective stabilizers for rigid polyvinyl chloride resin compositions, that is, resin compositions which are formulated to withstand high temperatures of the order of 375 F. and higher. A small degree of plasticization of such polymers is permissible provided this does not reduce the softening point of the resin to below the temperature to which it must be subjected. Such partially plasticized but still rigid resin compositions do not contain more than about 10% by weight of plasticizer. most rigid compositions generally contains no plasticizer at all.

A small amount, usually not more than 1.5%, of a parting agent, also can be included. Typical parting agents are the higher aliphatic acids and salts having from twelve to twenty-four carbon atoms, such as stearic acid, lauric acid, palmitic acid and myristic acid, lithium stearate and calcium palmitate, mineral lubricating oils, polyvinyl stearate, polyethylene and parafiin Wax.

The preparation of the stabilized composition is easily accomplished by conventional procedures. The selected stabilizer combination ordinarily is blended with the polyvinyl chloride resin, using, for instance, plastic mixing rollers, at a temperature at which the mix is fluid and thorough blending facilitated, milling the stabilizer with the resin on a 2-roll mill at from 300 to 400 F. for a time sufficient to form a homogeneous sheet, five minutes, usually. After the mass is uniform, it is sheeted off in the usual Way.

The following examples in the opinion of the inventor represent preferred embodiments of polyvinyl chloride resin compositions of his invention and exhibit the synergistic effect obtained thereby.

chloride) Mineral oil 0.75

The stabilizer was added in the proportion noted in Tables I and II, and was blended with the polyvinyl chloride and the mixture was fused on a two-roll mill and then tested in an oven at 350 F. and 375 F. for heat stability. The discoloration and clarity were noted, and

9 the color is reported in Tables I and II below wherein Table I refers to the tests conducted at 350 F. and Table II to the tests conducted at 375 F.

10 EXAMPLE HI The following materials were prepared in accordance with the procedure of Example I and tested for color and TABLE I Composition Number A B C D Stabilizing Composition 4.25 parts DBT bis DPGM plus 0.1 part 4,4'-butyl- 4.5 parts dibutyl tmbis- 0.1 part 4,4'-butyhdene-bisidene-bis-2-t-butyl-5- 4.5 parts dibutyl tin diootyl dipropylene glycol maleate 2-t-butyl-5-methylphenol methylphenol thioglycolate Time of Heating Color Color Color Color Initial--- Colorless Colorless Colorless Colorless Red do.. 9. do Do. Very pale yellow Very pale yellow. After 60 min 0 Pale yellow. After 75 min o ..do Light yellow. After 90 min Deeper yellow. Pale yellow Do. After 105 min Yellow brown. Light yellow. Do. After 120 min Charred do Yellow.

*Dibutyl tin-bis-dipropylene glycol maleate.

TABLE II Composition Number A B C D Stabilizing Composition 4.25 parts DBT bis DPGM plus 0.1 part 4,4'-butyl- 4.5 parts dibutyl tmbis- 0.1 part 4,4'-butyl1dene-bisidenebls-Z-t-butyl-fi- 4.5 parts dibutyl tin dioctyl dipropylene glycol maleate 2-t-butyl-5-methylphenol methylphenol thioglycolate Time of Heating Color Color Color Color Initial Colorless Colorless Colorless Colorless. After min Very pale yellow Pale yellow. After min Pale yellow 0. After min .do Yellow. After min Yellow 0. After min Brownish yellow. Orange yellow. After min d0 Orange brown. After min Brown Brown. After min Darker brown Deep brown.

*Dibutyl tin-bis-dipropylene glycol maleate.

The results clearly indicate that at both 350 and 375 F. the stabilizer compositions of this invention, exemplified by Composition C, have a stabilizing effect upon rigid polyvinyl chloride resins which is better than that of a typical sulphur-containing organotin stabilizer compound, dibutyl tin dioctyl thioglycolate, illustrated by Composition D. Composition D was observed to have a very pronounced and foul odor whereas Composition C, the composition embodying the stabilizer composition of this invention, did not exhibit any appreciable odor.

Compositions A, B and C together clearly indicate the synergistic effect obtained by means of this invention. Thus the result obtained either with A, dibutyl tin-bisdipropylene glycol maleate alone', or with B, 4,4-butylidene-bis-Z-t-butyl-5-methylphenol alone, are in no way comparable to the very favorable results obtained with C, the composition employing the two compounds together.

clarity at 350 F. and 375 F. Colors are reported in Tables III and IV, respectively.

Plastic composition: Parts by weight Geon 103 Ep (homopolymer of polyvinyl chloride) Mineral oil 0.75 Dibutyl tin-bis-dipropylene glycol maleate 4.25 Unhinded phenol listed in Tables III and TABLE III Composition Number E F G H Phenol 2,2 -bis-(4'hydroxyphenyl) 2-t-butyl-4-methoxyphenol 4-benzyloxyph enol Nonylphenol propane Time of Heating Color Color Color Color Initial Colorless Colorless Colorless Colorless. After min Very pale yellow .do Very pale yellow. After min o Very pale yellow Do. Alter min do--. do Do. After min Pale yello do Do. Aiter min do.-. ale yellow Light yellow. After min do- Light yellow Do. After min do. do Yellow. After min .do do Yellow Do.

TABLE IV Composition Number E F G H Phenol 2,2-bis-(4-hydroxypl1enyl) 2-t-butyl-4-methoxyphenol 4-benzyloxyphen0l Nonylphenol propane Time of Heating Color Color Color Color Initial Colorless Colorless Colorless Colorless. After 15 mm" Pale yellow- Pale yeliow.- Very pale yellow Slight yellow. After 30 min do do .do Pale yellow. After 45 min. Light yellow Light yellow. Yellow Yellow. After 60 min Yellow Yellow Deep yellow Deep yellow. After 75 min Deep yellow- Deep yellow- Dark olive Dark brown. After 90 min Light olive 've Dark brown Do. After 105 min Brown Brow-nu. o Do After 120 min Dark brown Dark brown do Do EXAMPLE III and 10% vinyl acetate. The stabilizer combination employed was 4.0 par-ts of dibutyl tin bis-(monoisooctyl 40 rnaleate) and 0.08 part of 4,4'-butylidene-bis-(Z-t-butyl- S-methyl phenol). The resulting composition remained colorless for a substantial period of time and had only In accordance with the procedure of Example I, the following ingredients were compounded and tested at 350 F. The colors obtained are reported in Table V.

Plastic Composition: Parts y Weight yellowed slightly at the end of two hours of heating at P 350 F., indicating that the stabilizer combinations of l{ l/ y p 45 this invention are also applicable to copolymers of vinyl Organotm compound As mdlcated chloride and vinyl acetate.

Mineral oil 0.75 EXAMPLE V As in the case of the preceding examples, Compositions J-M exhibited good stability at 350 F. without exhibit- The procedure of Example I was followed using difing the unpleasant odor characteristic of sulfur com- 50 ferent stabilizer combinations as noted and testing the pounds. compositions at 350 F. Results are indicated in Table VI.

TABLE V Composition Number J K L M Organotin Compound 4.25 arts of dibutyl tin- 4.25 parts of dibutyi tin- 3.6 parts of dibutyl tin- 3.8 parts of dibutyl tin-bisbisdipropyleue glycol bis-(Z-phenoxyethylmalebis-(2-ethoxyethylmaleate) (diethylene glycol maleate) maleate) ate) Time of Heating Color Color Color Color Colorless Colorless Colorless Colorless. Very pale yellow. do Very pale yellow Pele yellow. do Very pale yellow- Pale yellow Do.

Pale yellow Yellow.

o Do.

After 120 min do Deep yellow.

EXAMPLE IV Plastic composition: Parts by weight The procedure of Example I was repeated, using as the 103 P 150 resin 127.5 arts of Vinylite VYHH, a copolymer of Mlllefal 9 87% vinyl chloride and 13% vinyl acetate, and 22.5 parts 4,4-butyl1dene-b1s-2-t-butyl-5-methylphenol 0.1

of Vinylite VYNS, a copolymer of 90% vinyl chloride 75 Organotin compound As noted TABLE VI Composition Number Q R S T Organotin Compound 5.0 parts di-n-oetyl tin bis- 4.25 parts dibutyl tin bis- 4.l parts tri-n-oetyl tin (dipropylene glycol mono- (dipropylene glycol mono- 4.2 parts dibutyl tin bismonolsooctyl maleate maleate) maleate) (monoisooetyl fumarate) Time of Heating Color Color Color Color Initial Colorless Colorless Colorless Colorless. After 15 min. Very pale yellow Very pale yellow Very pale yellow. After 30 min do ..do Do. After 45 mln. Pale yellow Pale yellow Do. After 60 min. do do do Do. After 75 min Yellow rln Pale yellow Do. After 90 min do ight yellow. .do Pale yellow. After 105 mino fin do Do. After 120 min Deeper yellow do do Do.

EXAMPLE VI EXAMPLE VII This example illustrates the use of varying amounts of phenol compound in the stabilizer combination. The procedure of Example I was followed, with testing being carried out at 350 F. and 375 F. Results are tabulated in Tables VII and VIII.

Plastic composition: Parts by weight Geon 103 E 150. Mineral oil 0.75.

Dibutyl tin-bis- (dipropylene glycol monomaleate) 4.25. 4,4-butylidene-bis-2-tbutyl-S-methylphenol). As noted in Tables VII and VII.

The results indicate that the amount of phenol added to the composition may be varied widely without exerting an adverse effect upon the stabilization of the resin.

TABLE V11 A polyvinyl chloride polymer formulation was pre pared having the following composition.

Plastic composition: Parts by weight Geon 103 Ep (homopolymer of polyvinyl chloride) 240 Du Pont LD 313 (a chlorinated polyethylene containing approximately 38% chlorine) 60 lsooctyl epoxystearate 10 Composition Number U V W X Parts of Phenol Compound Time of Heating Color Color Color Color Initial Colorless Colorless Colorless Colorless. After 15 min Very pale yellow Very pale yellow- Very pale yellow- Very pale yellow. After 30 mm. Pale yellow Pale yellow Pale yellow- Pale yellow. After mln Light yellow Light yellow Light yellow Do. After mm d d d Light yellow. After min Do. After min" Do. After min- Do. After min .do --(10 d0 Do.

TABLE VIII Composition Number U V W X Parts of Phenol Compound Time of Heatlng Color Color Color Color Initial Colorless Colorless Colorless Colorless.

- Very pale yellow. After 30 min Pale yellow Pale yel w. Pale yellow. After 45 min Light yellow Light yellow Light yellow. After 60 min l0 Yellow/ Yellow. After 75 min Yellow do Deep yellow. After 90 min Brown-yellow Brown-yellow Olive. After 105 min Bro Brown Brown wn After 120 min Dark brown Dark brown Dark amber Dark brown.

both compositions were substantially identical in their Plasic composition: Parts by weight light yellow color. Composition Z gave otf an unpleasant Geon 103 Ep (polyvinyl odor characteristic of sulfur compounds whereas compo- Fhloride P Ym 150. sition Y, employing the stabilizer combination of this injyl Phthalate vention, was substantially odorless. (plasuclzer) This example illustrates the fact that the invention is Pamng agent AS ggi In Tables IX applicable t mixtures f p y e in which polyvinyl Stabilizer g in Tables 1X chloride is predominant. It also illustrates the use of a and X.

supplemental epoxy stabilizer along with the stabilizer combination of the invention. In this example, the supplemental stabilizer is isooctyl epoxy-stearate.

The results tabulated in Tables IX and X show that composition BB embodying the stabilizer combination of this invention retains its light color for longer periods of time than do polyvinyl chloride compositions which do not use the stabilizing combination. It is to be particularly noted that dibutyltin diacetate, which is not an organotin compound of this invention, in combination with 2,2-

tageous properties of the rigid compositlons of this 111- bis(4 hydroxyphenyl) propane 0T 4 4, buty1idene bis (2 vention, the following materials were blended as in Ex- 1 5 1 1 as 56m in cbmpositions EB and ample I and testfid for heat Stability at and GG, was not effective as astabilizer for polyvinyl chloride EXAMPLE VIII To show that 10% plasticizer does not affect the advan- 370 F. resin.

TABLE IX Composition Number AA B B C 0. DD

Stabilizing Composition 4.4 parts Dibutyltin di(isooetyl maleate) 0.1 part 4,4-butylidene- 4.5 parts Dibutyltin bis (-2-t-butyl-5- 2.8 parts Dibutyltm 1.5 parts 2,2-b1s(4-hydroxydi(isoootyl maleate) methylphenol) acetate phenyl) propane Parting Agent 0.3 part Lubricant (1,2- 0.3 part Lubricant (1,2- butylene glycol esters of butylene glycol esters of Montan wax acids) Montan wax acids) 0.75 part Mineral Oil 0.75 part Mineral Oil Time of Heating Color Color Color Color Initial. Colorless Colorless. Colorless Light pink. After 15 ID. Very pale yellow Very pale Intense yellow Dark brown-red. After min- Pale yello do.- Dark yellow- Very dark brown-red. Aiter min- ..-.do. do. Very dark yellow. Very dark brown. After min. Yellow- Pale yello do After min. ..doo.

..(lo After min- .-do- ..do- Very dark yellow with black edges...-

After min-. ..do ..do- Yellow with black areas and edges... After min ..do do Composition Number EE FF G G Stabilizing Composition 2.8 parts Dibutyltin diacetate 1.5 parts 4,4-butylidene bis 2.8 parts Dibutyltin diacetate 0.2 part 2,2'-bis (4-hydroxypheuyl)- (2-t-butyl-5-methyl 0.25 part 4,4-butylidene-bis(-2t-butylpropane phenol 5-methylphenol) Parting Agent 0.75 part Mineral Oil 0.75 part Mineral Oil 0.75 part Mineral Oil Time of Heating Color Color Color Initial. Colorless-.. Very pale yellow. After 15 m Pale yellow- Yellow-orange. After 30 min. Intense yellow- Orange. Aiter 45 min. Very dark yello (1 Dark orange. After 60 min. ....do Very dark orange with trace of black edge After 75 min. ...do (1 Very dark orange with black edge. After 90 min- Very dark yellow with black edges. Do. After 105 min.- Yellow with black areas and edges.

After 120 min TABLE X Composition Number AA B B CO DD Stabilizing Composition 4.4 parts Dibutyltin di(isooctyl maleate) 0. l part 4,4'-butylidene Lop-arts Dibutyltm blS (-2-t-buty1-5- 2.8 parts Dibutyltin 1.5 parts 2,2'-bis(4-hydroxyd1(1sooctyl maleate) methylphenol) diacetate phenyl)propane Parting Agent 0.3 part Lubricant (1,2- 0.3 part Lubricant (1,2- butylene glycol esters of butylene glycol esters of Montan wax acids) Montan wax acids) 0.75 part Mineral Oil 0.75 part Mineral Oil Time of Heating Color Color Color Color Initia1 Colorless Colorless Colorless Light pink. After m n." Intense yellow Dark brown-red. iger m n. gory garl yefiow Very dark brown.

or mm er ar e ow with black ed es. After 60 min Eeliow with faint brown Bla c ku Y e ges. After 75 min Yellow with brown edges do After 90 min Black Yellow with faint brown ed es.

Composition Number EE FF G G Stabilizing Composition 2.8 parts Dibutyltin diacetate 1.5 parts 4,4-butylidene bis 2.8 parts Dibutyltin diacetate 0.2 part 2,2'-b1s(4-hydroxyphenyD- (-2-t-butyl-5-methyl 0.25 part 4,4-butylidene-bis(-2-t-butylpropane phenol) fi-methylphenol) Parting Agent 0.75 part Mineral Oil 0.75 part Mineral Oil 0.75 part Mineral Oil Time of Heating Color Color Color Initial. Colorless Light pink Colorless. rigor m n Intense yellow gork brown-red Dark yellow.

er m n el'y dark brown-red Ver d 'k llowo an After m in Very dark yellow with black edg Oraiige ivitli black fn ii. After 60 m m 0 Black with orange areas. After 75 mln Black.

Having regard to the foregoing disclosure, the following is claimed as the inventive and patentable embodiments thereof:

1. A rigid polyvinyl chloride resin composition containing less than about 10% by weight of plasticizer and having increased resistance to deterioration when heated R C- at 375 F. consisting essentially of (a) a polyvmyl chloride resin; (b) an organotin compound having the struc- O ture: where R is aryl, alkyl or hydrogen; x and x are integers from one to four, the sum of x and x not exceeding 6;

4% 1 and phenols having the structure (12.) ..is 11-(0 2112) a (0K)! (OHM Z wherein R and R are selected from the group consisting of hydrocarbon groups and inertly substituted hydrocar- (R1)n (B1) bon groups having from one to about thirty carbon atoms, R is a hydrocarbon group having from one to about thirty carbon atoms containing an ethylenic double bond alpha to the carboxyl group where Z is selected from the group consisting of a single bond, oxygen, alkylene, alicyclidene, arylene, alkylenealicyclidene, and alkylene-arylidene, R and R are selected from the group consisting of hydrogen and alkyl having from one to about ten carbon atoms, and y y n 0 and 11 are integers, the sum of y and n is five, and the R is an organic group derived from a monohydric or di- 511m of )1 and "a is four; Said Phenol qg rg bemg hydlic alcohol is at least two 3 is at least one "3 present In 2211 amount to enhance the Stablllllng effect of is from zero to one, and the sum of :1 n and n is four; the ofganotlll Q P (c) a phenol compound having at least one hydrogen A COIPPOSIUOII as 111 6131111 1 f the Phenol atom at a i i Ortho to a phenolic h l group compound includes at least twoaromatic rings and whereselected from the group consisting of phenols having the the PhenO1 compound contalnspne Phenolic y y structure group attached to each aromatic ring.

(on) 2 3. A composition as in claim 1 wherein the phenol I compound is 4,4 butylidene bis (2-t-butyl-5-methylphenol).

4. A composition as in claim 1 wherein the phenol compound is 2-t-butyl-4-methoxyphenol.

5. A composition as in claim 1 wherein the phenol compound is nonylphenol.

6. A composition as in claim 1 wherein the phenol compound is 2,2'-bis-(4-hydroxyphenyl) propane.

7. A composition as in claim 1 also containing an Organic epoxy compound as a supplemental stabilizer.

8. A rigid polyvinyl chloride resin composition containing no plasticizer and having increased resistance to deterioration when heated at 375 F. consisting essentially of (a) a polyvinyl chloride resin; (b) an organotin compound having the structure wherein R and R are selected from the group consisting of hydrocarbon groups and inertly substituted hydrocarbon groups having from one to about thirty carbon atoms, R is a hydrocarbon group having from one to about thirty carbon atoms containing an ethylenic double bond alpha to the carboxyl group R is an organic group derived from a monohydric or dihydric alcohol, n is at least two, n is at least one, n is from zero to one, and the sum of n I1 and n is four; (c) a phenol compound having at least one hydrogen atom at a position ortho to a phenolic hydroxyl group selected from the group consisting of phenols having the structure from the group consisting of hydrogen and alkyl having wherein R is selected from the group consisting of hydrogen, halogen and the following organic radicals having from one to thirty carbon atoms: hydrocarbon, aromatic ring condensed with the phenol ring, heterocyclic, alkoxy, and acyl where R is aryl, alkyl, or hydrogen; x and x are integers from one to four, the sum of x; and x not exceeding 6; and phenols having the structure where Z is selected from the group consisting of a single bond, oxygen, alkylene, alicyclidene, arylenc, alkylenealicyclidene and alkylene-arylidene, R and R are selected from one to about ten carbon atoms, and y y I1 and m, are integers, the sum of y and n is five, and the sum of y and n is four; said phenol compound being present in an amount to enhance the stabilizing effect of the organotin compound.

References Cited UNITED STATES PATENTS 2,625,521 1/1953 Fischer et a1 26023 3,019,247 1/1962 Mack et al 260-429.7 3,075,940 1/1963 Pazinski et a1 2603 1.8

DONALD E. CZAJA, Primary Examiner V. P. HOKE, Assistant Examiner US. Cl. X.R. 

